- Relies on storing data in quit.blend in the temp dir which may be be deleted on reboot (depending on the platform, it's deleted here).
- By default this still shows the "Save Changes..." popup.
- It might be older than the currently saved blend file if you have multiple Blender instances open.
Generally this isn't so useful if you have multiple Blender's open.
Mostly my concern is this is a way to change the behavior of file IO
that I don't think many people use, and relies on the temp directory
which might get clobbered.